The present invention relates generally to a method for detecting and excising nonpalpable lesions and, more particularly, to a hematoma-directed ultrasound guided excisional breast biopsy.
Increased screening mammography has led to over 1,000,000 breast biopsies performed yearly in the United States. An increasing number of these biopsies are for nonpalpable mammographic abnormalities and less than one-third are visible with ultrasound. Available options for biopsy of these mammographic abnormalities have included needle localization excisional breast biopsy (NLBB) or percutaneous stereotactic core needle breast biopsy (SCNBB).
Magnetic resonance imaging (MRI) of the breast has allowed for the visualization of lesions previously undetected by mammography. Despite the availability of MRI guided needle localization techniques at medical institutions, the patient is still subjected to the disadvantages and complications inherent to this method of biopsy. Although NLBB most often results in the successful removal of the targeted lesion in mammographically detected lesions, the miss rate varies from 0 to 22% [Snider HC et al., Intraoperative ultrasound localization of nonpalpable breast lesions, Ann Surg Oncol 6(3):308-314 (1999); Rissanen T J et al., Wire localized biopsy of breast lesions: a review of 425 cases found in screening or clinical mammography, Clin Radiol 47:14-22 (1993); Hasselgren P O et al., Breast biopsy with needle localization: accuracy of specimen x-ray and management of missed lesions, Surgery 114:836-42 (1993); and Homer M J et al., Prebiopsy needle localization: methods, problems, and expected results, Radiol Clin North Am 30(1):139-153 (1992)]. The rate is unknown for MRI NLBB, where even thinner wires are used and where the technology is not universally available.
Specimen mammography is used to confirm excision of the targeted lesion after NLBB. In contrast, xe2x80x9cspecimen MRIxe2x80x9d is not possible because MRI requires living tissue with a blood supply to demonstrate areas of enhancement of the targeted lesion. Confirmation of removal requires a separate MRI of the remaining breast tissue in the patient on a separate day.
Although NLBB is considered the xe2x80x9cstandardxe2x80x9d for removal of mammographically-detected, nonpalpable breast lesions, disadvantages include the possibility of significant vasovagal reactions which occur in 10 to 20% of patients, the discomfort of the wire, and the possibility of wire transection or migration [Rissanen T J et al, Wire localized biopsy of breast lesions: a review of 425 cases found in screening or clinical mammography, Clin Radiol 47:14-22 (1993); and Homer M J et al., Prebiopsy needle localization: methods, problems, and expected results, Radiol Clin North Am 30(1):139-153 (1992)].
The proven accuracy of SCNBB as well a better rate of margin clearance when the diagnosis of cancer has been established prior to definitive procedure has influenced many surgeons in favor of SCNBB [Yim J H et al., Mammographically detected breast cancer-benefits of stereotactic cores versus wire localization breast biopsy, Ann Surg. 223:688-700 (1996); Israel P S et al., Stereotactic needle biopsy for occult breast lesions: a minimally invasive alternative, Am Surg 61:87-91 (1995); Velanovich F et al., Comparison of mammographically guided breast biopsy techniques, Ann Surg 229(5):625-33 (1999); Fuhrman G M et al., Image-guided core-needle breast biopsy is an accurate technique to evaluate patients with nonpalpable imaging abnormalities, Ann Surg. 227(6):932-39 (1998); and Meyer J E et al., Large-core needle biopsy of nonpalpable breast lesions JAMA 281(17):1638-41 (1999)]. However, when the results of SCNBB require further evaluation, NLBB has been the only tool available to the surgeon.
There, thus, remains a need to develop an alternative method that can be used to excise nonpalpable lesions and, at the same time, provide a greater comfort level for the patient.
The present invention is directed to a hemotoma-directed ultrasound guided method for detecting and excising nonpalpable lesions in a patient. The method can be used not only to localize a MRI-detected lesion, but also to outline the targeted lesion for complete excision and to obtain margins. The method of the present invention overcomes many of the disadvantages associated with traditional NLBB, for example, discomfort, significant vasovagal reactions (i.e., vomiting, nausea, fainting), frequent delay of surgery, wire transection or migration, significant miss rate, and additional imaging to confirm lesion removal.
Twenty patients with nonpalpable breast lesions detected by MRI only were enrolled in a single institution trial. A hematoma comprising about 2-5 ml of the patient""s own blood was injected into the breast to target the nonpalpable lesion. Intraoperative ultrasound of the hematoma was used to direct the excisional biopsy.
Ninety-five percent of the lesions detected by MRI were successfully localized by hematoma injection. All of the hematomas used to recognize targeted lesions were successfully identified at surgery by ultrasound and then removed without complication. Eight (40%) of the lesions were malignant with an average tumor size of 12xc2x16 mm (range 4-25 mm). The remaining 12 lesions (60%) comprised papillomas, sclerosing adenosis, radial scars, fibroadenomas, and areas of a typical ductal hyperplasia.
The hematoma can be created by a blood injection using the patient""s own blood or naturally by stereotactic core needle biopsy (SCNBB). The hematoma resulting from SCNBB can be used to localize the SCNBB site with intraoperative ultrasound for excision.
20 patients had SCNBB followed by intraoperative ultrasound-guided excision. The previous SCNB site in 19 patients was successfully visualized with intraoperative ultrasound and excised at surgery. One patient had successful removal of the targeted area under ultrasound guidance, but failed to show removal of the clip on the initial specimen mammogram.
The results demonstrate the effectiveness of hematoma-directed MRI-guided breast biopsy for nonpalpable lesions by blood injection and by needle biopsy using stereotactic guidance. This novel procedure is potentially more comfortable for patients than current procedures because no wire or needle is left in the breast. The procedure of the present invention is technically faster and easier because ultrasound is used to visualize directly the location of the hematoma at surgery and to confirm lesion removal in the operating room by specimen ultrasound. The hematoma can be inserted into the patient several days before the biopsy, resulting in greater flexibility in scheduling the biopsy and alleviation of the fear of wire migration that frequently occurs with NLBB.
In addition to MRI-detected lesions, it is contemplated that the method of the present invention can be used to guide the excision of lesions visualized by other modalities including mammography, PET scanning, and scintimammography.
In one aspect of the present invention, a method for detecting and excising nonpalpable lesions, comprising the steps of: (a) injecting at least one hematoma into a mammal""s breast to target a nonpalpable lesion; wherein the hematoma comprises approximately 2 ml to about 5 ml of the mammal""s own blood; (b) detecting the location of the targeted lesion using MRI; and thereafter (c) excising the targeted lesion. The method may further include the step of confirming the excision of the lesion by ex vivo ultrasound. The hematoma is placed in the mammal""s breast for a period of about several hours to about several days before excision of the targeted lesion. The hematoma may be combined with at least one composition for injection into the mammal. The mammal may be a human or an animal. Most importantly, the method may be performed in any organ, not just the breast.
In another aspect of the invention, at least one hematoma is produced in the mammal""s breast by stereotactic core needle biopsy to target a nonpalpable lesion. Detection of the targeted lesion is achieved by ultrasound followed by excision of the targeted lesion.